With thousands of species at risk of extinction, scientists have devised a radical plan: a vault filled with preserved samples of our planet’s most important and at-risk creatures located on the moon. An international team of experts says threats from climate change and habitat loss have outpaced our ability to protect species in their natural habitats, necessitating urgent action. A biorepository of preserved cells, and the crucial DNA within them, could be used to enhance genetic diversity in small populations of critically endangered species, or to clone and create new individuals in the worst-case scenario of extinction. A repository to safeguard biological samples from disaster is not a new idea. The Svalbard global seed vault on a remote Norwegian island in the Arctic Circle provides frozen storage of seeds to ensure important food crops can be re-established if wiped out by disease or drought. Recent flooding as a result of warm temperatures, however, has proven that not even Svalbard is safe from the effects of climate breakdown. “If there had not been people there, flooding could have damaged the biorepository,” said the proposal’s lead author, Dr Mary Hagedorn of the Smithsonian’s national zoo and conservation biology institute. War also poses a threat to biorepositories on Earth, she noted, citing the destruction of Ukraine’s seed bank in 2022. “So all in all, the idea of having a really secure, passive biorepository for safeguarding Earth’s biodiversity seems like a really good idea.” The proposed lunar biorepository, as described in the journal BioScience, would be beyond the reach of climate breakdown, geopolitical events or other Earth-based disasters. The moon’s naturally frigid environment means samples would remain frozen year-round without the need for human involvement or an energy source. By taking advantage of deep craters near the polar regions that are never exposed to sunlight, the moon is one of few places that can provide the ultra-low temperature of -196C necessary to preserve the samples in a way suitable for future cloning. “In order for cloning to be an option, one needs cells that are alive,” said Dr Beth Shapiro, a professor of ecology and evolutionary biology at UC Santa Cruz and chief science officer of the de-extinction company Colossal Biosciences, who was not involved in the lunar biorepository proposal. This means it is not possible to clone a woolly mammoth from DNA fragments, she explained, but de-extinction is possible if tissue samples are collected and stored in a way that ensures the cells stay alive. Establishing a lunar biorepository would involve numerous challenges, but biology is not the main one. Hagedorn’s team has already used cryopreservation – a technique where cells are stored at temperatures so cold that all biological activity stops – to successfully preserve living cells from the starry goby fish. The starry goby is not endangered, but it plays an essential role in maintaining the health of coral reef ecosystems. Besides those facing the imminent risk of extinction, the proposed repository would prioritise species with important functions in their environment and food webs. Through careful selection, those housed could be used to re-establish an extinct population on Earth or even to terraform another planet. Hagedorn believes the biorepository proposal will come to fruition, although perhaps not in our lifetime: “We know how to do this and can do this and will do this, but it may take decades to finally achieve,” she said. Given the costs and challenges involved, critics may suggest efforts should focus on preserving species before they come extinct. Hagedorn, however, said both strategies were necessary to ensure the conservation of as many species as possible. “When we think linearly, and not in parallel, we get in trouble. If you say: I’m going to do it this way, and it doesn’t work, what’s plan B?”, she said. Crucial next steps will be to develop packaging for the cryopreserved samples that can withstand the conditions of space, and to work out the logistics of transporting samples to the moon. Envisioning a near-future where exploration of the moon’s resources means more frequent space travel, Hagedorn suggested delivery of small parcels containing thousands of cryopreserved samples could be added on to existing lunar trips. With so much of the proposal still in the realm of science fiction, the scientists say they hope their paper will generate excitement, new ideas and new international partners – and perhaps a little controversy – about the extreme actions necessary to protect biodiversity.